p-tau181/Aβ42 ratio

1. p-tau181/Aβ42 ratio predicts cognitive function in humans (γ2 = -4.14, p = 0.046).

   “Baseline CSF p ‐tau181/Aβ 1‐42 ratio was negatively associated with a two‐year change in delayed recall scores (γ2 = ‐4.14, z = ‐2.01, p = 0.046).”

   Humans2 yearsn = 92

   Delayed recall predicts change in cerebrospinal fluid biomarkers over two years

   AAIC 2025 abstract·26 Dec 2025

1. Functional impairment is associated with p-tau181/Aβ42 ratio in humans (Beta=21.35; 95%CI: [6.79‐37.89]; p = 0.003).

   “Persistent FI was associated with a significantly higher ptau181/Aβ42 ratio (Beta=21.35; 95%CI: [6.79‐37.89]; p = 0.003)”

   Humanscompared to no FIcerebrospinal fluidn = 1,001

   Functional impairment in association with biofluid biomarkers of Alzheimer's disease in dementia‐free older adults

   AAIC 2025 abstract·26 Dec 2025

1. p-tau181/Aβ42 ratio is associated with amyloid PET SUVR in humans (r = 0.15, p = 0.005).

   “Blood p ‐Tau181 and p ‐Tau181/Aβ42 were positively correlated with whole‐brain Aβ SUVr ( r = 0.12, p = 0.028; r = 0.15, p = 0.005).”

   Humanssubjective cognitive declineplasma

   Study on Blood Biomarkers of Subjective Cognitive Decline

   AAIC 2025 abstract·24 Dec 2025

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1. p-tau181/Aβ42 ratio is associated with dual decline in cognitive and motor functions in humans (OR = 1.18, 95% CI: 1.12;1.25).

   “phosphorylated tau181/amyloid-β42 ratio (OR = 1.18, 95% CI: 1.12;1.25) were associated with the highest risk of a dual decline pattern among study participants.”

   Humansserum

   ASSOCIATION BETWEEN SERUM BIOMARKERS OF ALZHEIMER’S DISEASE AND “DUAL DECLINE” IN COGNITIVE AND MOTOR FUNCTIONS

   GSA 2024 abstract·31 Dec 2024

1. p-tau181/Aβ42 ratio predicts Alzheimer's disease in humans.

   “Elevated levels of AD biomarker p-tau181/Aβ42, by itself or combined with a low Aβ42/Aβ40 level, predicts clinically diagnosed AD.”

   Humansby itself or combined with a low Aβ42/Aβ40 level

   Risk of Alzheimer's disease is associated with longitudinal changes in plasma biomarkers in the multi-ethnic Washington Heights-Hamilton Heights-Inwood Columbia Aging Project (WHICAP) cohort

   Alzheimer's & dementia : the journal of the Alzheimer's Association·6 Jan 2024

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1. p-tau181/Aβ42 ratio raises the risk of dementia in humans.

   “Higher baseline levels of p-tau181/Aβ42 ratio were associated with an increased risk of incident dementia.”

   Humansin cognitively unimpaired older adults

   Risk of Alzheimer's disease is associated with longitudinal changes in plasma biomarkers in the multi-ethnic Washington Heights-Hamilton Heights-Inwood Columbia Aging Project (WHICAP) cohort

   Alzheimer's & dementia : the journal of the Alzheimer's Association·6 Jan 2024

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